Technical Field
The inventive concept relates to a semiconductor device, and more particularly, to a mobile device capable of controlling memory and system performances based on a number of requests to be processed and a method of controlling the mobile device.
Discussion of the Related Art
Mobile devices are increasingly being used. Examples of mobile devices include a smart phone, a tablet personal computer (PC), a digital camera, an MP3 player, a personal digital assistant (PDA), etc. An increase in driving of multimedia and throughput of various data accelerates the application of high-speed processors and mass storage media to such mobile devices. A variety of application programs are driven on a mobile device. To drive a variety of application programs, the mobile device includes semiconductor devices such as a working memory (e.g., dynamic random access memory (DRAM)), a nonvolatile memory, an application processor (AP), etc. As high performance is expected in a mobile environment, the degree of integration and driving frequencies of the above-mentioned semiconductor devices continuously rise.
In a mobile device, performances of a processing unit and a DRAM are rapidly being improved. However, a performance of a storage device, which is used as a nonvolatile storage medium, does not keep up with the performance improvements of the processing unit and the DRAM. Correspondingly, an overall performance of the mobile device that a user experiences is affected by an access speed to the storage device. For example, when the access speed to the storage device in a multi-tasking environment is slow, the quality of service (QoS) that the user experiences is lessened.
Various input/output scheduling techniques for the storage device are used to provide the user with high-quality services. In certain input/output scheduling techniques, a performance of a current access operation is based on a previous access parameter. However, such techniques may not be effective when an access request to the storage device rapidly increases or decreases.